Finishing apparatus and method



March 26,1940. WALLACE 2,195,065

FINISHING APPARATUS AND METHOD Filed NOV. 5, 193B A T T ORNE V5.

6/ IN VE N TOR 6F 6: 0/! W0 ,4. MILL/I 05. E5..- BWMMQwW Patented Mar.26, 1940 UNITED STATES PATENT OFFICE FINISHING APPARATUS AND METHODApplication November 5, 1938, Serial No. 238,947

7 Claims.

This invention relates to an improved lapping apparatus and method.

More particularly. the invention has reference to an improved lappingapparatus of the type delscribed and claimed in my co-pendingapplication, Serial No. 132,688, filed March 24, 1937,

' The main object of the invention is to provide between an articlebeing lapped and the lapping element, a relative movement which is theresult- 1 ant of a plurality of diiferentsimultaneouslycomponentmovements of the lapping element and the work; This is accomplished byrotating and rapidly reciprocating the lapping element and revolving androtating the work while slowly reciprocating the lapping element acrossthe face of the work. 3

Another object of the'invention resides in the provision of relativemovement between a lapping element and a piece of work which is theresultfl ant of simultaneous relative-rotating and revolving actionsbetween the latter and the'former, and als'obodily shifting of thelapping element across the face of the work while the lapping elementreciprocates independently of the aforesaid 3| bodily movement, andselected combinations thereof.

A further object of the invention is to provide an impro'vedmethod forlapping a piece of work which comprises simultaneously rotating the sowork about one axis and revolving the same about another axis whilerotating and reciprocating the lapping element and shifting the entirelapping tool bodily across the face of the work, or selectedcombinations of these movements.

Other objects and advantages of the invention will be more apparent fromthe following description taken in connection with the accompanyingdrawing, in which:

Fig. 1 is a side elevational view, partly in sec- 0 tion, of a lappingmachine embodying the invention.

Fig. 2 is a fragmentary vertical sectional view taken on the line 2-2 ofFig. 1.

Fig. 3 is an enlarged plan view taken as indigs cated by the line 3-3 ofFig. l.

In the form of the invention illustrated in the drawing, the improvedlapping machine comprises a base structure, generally designated bythenumeral I0, having a lower horizontal bed 50 portion H and anupstanding vertical portion l2. Formed in the bed portion I l is acylindrical bore [3 having counterbore recesses H at its oppositeextremity. A tubular journal member i5 is rotatably supported in thecylindrical bore 83 by bearings la disposed in the recesses it. Eachbearing l6 comprises inner and outer bearing races l1 and I8,respectively, between which is disposed a series of ball bearings iii.The tubular journal member I5 is provided at its upper end with a radialflange 20 which is seated upon the 5 upper edge portion of the innerbearing race IT, as illustrated in Fig. 1. Formed in the upper endportion of the journal member I5 is a counterbore 2! in which a bushing22 is disposed. The lower end portion of the journal I5 has a counter-10 bore, as illustrated at 23, for the reception of a roller bearingunit 24 which is removably held in the lower end portion of the journalmember l5 by a threaded plug 25.

A.work supporting table 26 having a spindle portion 21 journalled in thebushing 22 and bearing unit 24 is rotatably mounted in the journalmember IS, the bushing 22 and bearing unit 24 beingso constructed andarranged as to bring the rotative axis of the spindle 2'! into eccentricrelationship with respect to the rotative axis of the journal member I5.This may be accomplished by suitable bushing and bearing construction orby forming the counterbores 2| and 23 of the journal member l5 eccentricwith respect to the 25 axis of rotation of the latter. The lower endportion of the spindle 21 is provided with a reduced end portion 28 onwhich a pulley 29 is non-rotatably fixed. A collar 30 having a beltgroove 3| therein is non-rotatably fixed on the lower end 80 portion ofthe journal member 15 which extends below the lower extremity of the bedportion ll of the base structure. The pulley 29 and collar 30 aredrivingly connected by belts 32 and 33 to driving pulleys 34 and 35mounted on the shaft 35 36 of an electric motor 31, or other suitabledriving means carried by the base structure. Belt tensiom'ng members 38and 39 having wheels on their free end portions are provided for takingup the slack in the belts 32 and 33. The work table 40 comprises a disc42 mounted on the upper end of the spindle 21.

A piece of work 451s shown detachably secured to the upper side of thedisc 42 by bolts 46, or other suitable means. The work 45 may com- 45prise any part which has a substantially plane surface 4! to be lapped.

The upstanding portion P2 of the base structure l I is provided with ahead member 48 which is slidably mounted at 48' for movement in a 50plane normal to the axis of the work table 28 and which has formedtherein a cylindrical bore 49. The head48 extends over the work table 26and the bore registers vertically with the surface portions of the work45 to be lapped. Vertically 5 reciprocably mounted in the bore 45 is asleeve 55 having rack teeth 5| formed on its outer periphery and meshedwith the teeth of a rack gear 52 mounted on a shaft 53 which isjournalled in the head structure 45 and provided with an operatinghandle (not shown) by which the sleeve 55 may be raised and lowered, asdesired.

The sleeve 50 serves as a support for the lapping or abrading tool,generally designated by the numeral 54, which includes a tubular baseportion 55 rotatably mounted in the sleeve 50. The tubular base portion55 has a head part 55 on its lower extremity in which a channel 51 isprovided. The channel 51 is disposed in a plane substantially normal tothe axis of rotation of the base portion 55 of the tool and has a loweropen side restricted by cleats 55. Slidably mounted in the channel 51 isa block 59 having spaced downwardly extending flanges 50 on its lowerextremity between which is disposed a lapping element carrier 5| havinga lapping or abrading element 52 comprising natural stone, bondedsynthetic abrading material, or other suitable abrading composition. Theabrading element carrier 5| is 'pivotally attached to the spaced flanges55 of the head 55 by a removable pin 53.

The tubular body portion 55 of the tool 54 has an upper external endportion 54 which extends upwardly of the head 48 and on which isnonrotatably mounted a pulley wheel 55. A section of the tubular baseportion 55 between the pulley wheel 55 and the flange 48 is threaded asillustrated at 55 for accommodating the attachment thereto of lockingnuts 61 which are adapted to have thrust bearing engagement with theupper extremity of the sleeve 50 as illustrated in Fig. 1. The pulleywheel 55 is drivingly connected by a belt 55 with a motor 69 mounted onthe hea member 45.

Operation of the motor 69 rotates the tubular body portion 55 of theabrading tool 54 about its vertical axis, thereby similarly rotating theabrading element 52 bodily with respect to the work 45. During rotatingof the abrading ele ment 52 in the foregoing manner, the abradingelement is also reciprocated relative to the tubular base portion of thetool by a motor having a shaft 1| on the lower extremity on which isprovided an eccentrically located driving pin 12. The driving pin 12 hasa bushing 13 thereon which is slidably mounted in an elongated slot 14formed in the slide block 59. During rotation of the shaft 1! the block59 is reciprocated in the channel 51 in a direction substantially normalto the axis of the tool. The motor 10 is preferably operated at arelatively high speed in order to subject the block 59 and the abradingelement 62 carried thereby to reciprocatory movement approaching avibratory order. This reciprocation of the abrading element 62 occurssimultaneously with the bodily rotation thereof by the motor 59, whichrotation preferably occurs at a comparatively slow speed.

In the tool shown in Figs. 1 and 2, the motor shaft 1| is preferably soconstructed with respect to the outside axes of the tubular base portion55 as to maintain an eccentric relationship between these two rotativeaxes. If desired, however, the axes of rotation of the shaft 1| andtubular body portion 55 of the tool 54 may be concentric. The motor 10is preferably supported by a fixture 15 which merely rests upon theupper extremity of the tubular body portion 55 and which is providedwith a torque arm 16 which engages a stop 11 mounted on the upperextremity of the head member 41 in order to prevent turning of the motor10 in unison with, or by the tubular base portion 55.

Suitable means, such as a motor 80, are employed to shift bodily theentire lapping tool 54 across the face of the work. The motor 55 ismounted on the bed portion H and preferably acts through a speedreducing gear mechanism 8| to revolve the eccentric member 82 which isoperatively connected with the head member 48 by a link 83.

Referring to the operation of the illustrated lapping apparatus, thelapping element 52 is placed in engagement with the surface 41 of apiece of work 45 by allowing the tool to move downwardly until the lowersurface of the lapping element engages the surface 41 of the work. Thetool 54 may be lifted to accommodate removal of the work 45 by rotatingthe rack gear 52 by manipulation of a handle (not shown) on the shaft 53by which the gear 52 is carried. While the lapping element 62 is inengagement with the surface 41 of the work, the latter may be rotatedabout the axis of the spindle 21 and revolved about the eccentric axisof the journal member I5. During this movement of the work, the lappingelement 52 is reciprocated by the motor 10 and rotated by the motor 59and associated driving structures. The head member 48 is preferablyreciprocated by the motor 80 at a relatively low rate to bodily shiftthe entire lapping tool 54 across the face of the work 45 while thelapping element is reciprocated and rotated by motors 10 and 69respectively.

During the operation of the lapping apparatus there is a relativemovement between the work and the lapping element which is the resultantof a plurality of different simultaneous component movements of thelapping element and the work by rotating and rapidly reciprocating theformer, and by revolving and rotating the latter while reciprocating thelapping tool bodily across the face of the work at a relatively slowspeed. If desired, the work may be rotated about the axis of the spindle21 only while the journal member I5 is held at rest during combinedrotating and reciprocating actions of the lapping element and bodilyreciprocation of the head member 48; or, the work may be revolved byrotating the journal member l5 without drivingly rotating the work aboutthe axis of the spindle during the lapping operation. Either the rapidreciprocating or the rotating movement of the lapping element 62 may bediscontinued during either of the foregoing modes of movement of thework, if desired. It is preferable, however, to rotate and rapidlyreciprocate the abrading element 62 and revolve and rotate the work 45,and reciprocate the abrading tool 54 bodily during the abradingoperation in order to provide relative movements between the abradingelement and the surface of the work operated upon which is a resultantof a greater number of component movements so as to guard againstrepeated applications of localized hard or sharp particles of abradingmaterial to the same increment of area of the surface operated upon. Inthis manner, the formation of scratches on the surface being abraded isavoided and complete removal of all the machine-formed grooves and otherirregularities of the surface 41 is rapidly accomplished.

Although but one specific embodiment of the invention is herein shownand described, it will be understood that various changes in the size,shape and arrangement of parts may be made without departing from thespirit of the invention.

What I claim is:{

1. Finishing apparatus comprising a base structure, a carriage rotatablymounted on said base structure, means for supporting work including awork table rotatably mounted on said carriage in eccentric relationshipwith respect to the axis thereof, means for simultaneously rotating saidcarriage and said work table about their respective axes, an abradingtool having an abrading element reciprocably mounted therein anddisposed in opposing relationship with respect to said work table andincluding means for reciprocating said abrading element at a rateapproaching vibratory order relative to said work table and relative towork supported thereby during simultaneous rotating and revolvingmovement of the latter about the axis of said work table and about theaxis of said carriage respectively, and means for riciprocating saidabradlng element, while vibrating, across the face of said work at arelatively low rate and while said work revolves and rotates.

2. Finishing apparatus comprising a base structure, a carriage rotatablymounted on said base structure, means for supporting work including awork table rotatably mounted on said carriage in eccentric relationshipwith respect to the axis thereof, means for simultaneously rotating saidcarriage and said work table about their respective axes, an abradingtool having an abrading element rotatably and reciprocably mountedthereon and disposed in opposing relationship with respect to said worktable and including means for reciprocating said abrading element at arate approaching vibratory order and for rotating said abrading elementduring application thereof to work supported on said work table, andmeans for reciprocating said abrading element across the face of saidwork at a relatively low rate while vibrating and rotating and whilesaid work revolves and rotates.

3. Lapping apparatus comprising a base struc ture, a carriage rotatablymounted on said base structure, means for supporting work including awork table rotatably mounted on said carriage in eccentric relationshipwith respect to the axis thereof, means for simultaneously rotating saidcarriage and said work table about their respective axes, a shiftablehead member supported by said base structure and adapted to move in aplane substantially normal to the axis of said carriage, a lapping toolcarried by said head member and having a lapping element rotatably andreciprocably mounted thereon and disposed in opposing relationship withrespect to said work table and including means for simultaneouslyreciprocating said lapping element at a rate approaching vibratory orderand rotating said lapping element, and means for reciprocating said headmember at a relatively slow rate while said element vibrates and rotatesand while said work revolves and rotates.

4. Lapping apparatus comprising a base structure. a carriage rotatablymounted on said base structure, means for supporting work including awork table eccentrically mounted on said carriage, apparatus forrotating said carriage and said work table about their respective axes,ashiftable head member supported by said structure and adapted to movein a .plane substantially normal to the axis of said carriage, a lappingtool carrier rotatably mounted on said head member, a lapping toolmounted on said tool carrier in eccentric relationship with respect tothe axis of the latter and having a reciprocably mounted lapping elementthereon disposed in opposing relationship with respect to' said worktable, said tool including means for simultaneously rotating said toolabout its rotative axis and reciprocating said lapping element at arelatively rapid rate, and means for reciprocating said head member at arelatively low rate while rapidly reciprocating and rotating saidlapping element and while said work revolves and rotates.

5. Lapping apparatus comprising a support, a carriage rotatably mountedon said support, means for supporting work including a work tableeccentrically mounted on saidcarriage, apparatus for rotating saidcarriage and said work table about their respective axes, a shiftablehead member supported by said structure and adapted to move in a planesubstantially normal to the axis of said carriage, a lapping toolcarriage rotatably mounted on said head member, a lapping tool mountedon said tool carriage in eccentric relationship with respect to the axisof the latter and having a reciprocably mounted lapping element thereondisposed in opposing relationship with respect to said work table, saidtool including means for simultaneously revolving said tool about theaxis of said tool carriage and reciprocating said element at arelatively rapid rate, and means for reciprocating said head member at arelatively low rate while revolving said tool and rapidly reciprocatingsaid element and while said work revolves and rotates.

6. The method of lapping a'surface of a workpiece which comprisesapplying a lapping element to said surface and rotating the workpieceabout one axis while revolving the same about another axis, andreciprocating said lapping element while rotating it and traversing itbodily across said surface.

7. The method of abrading a surface of a workpiece which comprisesapplying an abrading element to said surface and rotating the workpieceabout one axis while revolving the same about another axis, andreciprocating said abradlng element and revolving it while at the sametime bodily traversing it across said surface.

DAVID A. WALLACE.

CERTIFICATE- .OF CORRECTION. Patent No. 2,19 ,05 March 26, 191

mwmA. WAILACE.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,first column, line 66, for the word outside read -rotative--; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record. of the case in the Patent Office.

Signed. and sealed this 25rd day of July, A. D. 191m.

Henry Van Arsdal (Seal) Acting Commissioner of Patents

